The Bell System introduced the dial telephone
in 1919 with Western Electric Company manufacturing the equipment used.
In 1922 the Bell System introduced dial service to the large metropolitan
area of New York.

The # 2 dial

To most of us, a Western Electric Type 2 -dial
is characterized by a finger stop screwed to the outside of the case and
a loud clickety clack sound made when dialing. However, the continual
engineering updating by Western Electric presents a large group of differences.

The first obvious difference you will find in
examination of these early dials is the marking on the finger stop. These
markings consist of: 2AA, 2AB, 2AE, 2CB, 2EA, 2EB, 2HA, 2HB and unmarked.
The first letter indicates the type of switch contacts mounted on the rear
of the dial. The "A" type of contact was the most used since it was
intended for use in telephones such as the candlesticks. This "A"
type of contact has four screw terminals on the switch assembly.
The "E" type of contact was the same contact assembly as the "A" type but
with each of the five contact points brought out to a screw terminal.
The "E" type was intended for use in telephone company trouble desks and
repair stations. The "H" type of contact assembly was created for
the new "French" style B (202) telephone introduced in 1928-1929.
This contact style, used continuously by the Bell System until the mid
1950's, also had five screw terminals. The "C" type of contact was
the same as the "A" type, and may have been used in coin collector applications.
The "C" type dial was used on repairmen's hand test telephone sets.
It is factory adjusted to run at 12 PPS rather than 10 PPS. This
was intended to permit technicians to test dialing accuracy under more
severe conditions than subscribers would experience using normal 10 PPS
dials

The "C" type of dial differed from the "A" type
of dial in that it had speed adjustment marks on the governor similar to
the type 4 dial. The second letter on the finger stop indicates the
style of the numbers and letters on the face of the dial. The letter
"A" indicated numbers only on the dial face and was intended for use in
rural areas with one central office. The letter "B" indicated numbers
and letters on the dial face. It was intended for use in metropolitan
areas which had many branch exchanges that were given names rather than
numbers. The letter "E" also indicated numbers and letters but in
a different arrangement from the "B" type. The "E" type was probably
for party line use. The 2_E type has only the party letters "J, M, R, and
W" located in the same holes (5, 6, 7 & 9) in which they would appear
on a 2_B dial. These letters were probably selected for minimum chance
of confusion when passed verbally to an operator. The #9 catalog
illustrates this number plate for a #4 dial, which almost certainly would
have matched what appeared on a #2 dial.

Occasionally a type 2 dial will be encountered
which has been remarked by the Bell System. For example, 2AE dial
restamped 2AXA or a 2AB restamped 2AXA, where the "X" indicates that the
letter has been overstamped to obscure it, and a new letter stamped beside
it. In addition, dials may be encountered which have been converted
to different contact styles as, for example, the conversion of an "A" contact
to an "E" contact.

The second most obvious difference observed is
the method in which Western Electric marked their name on the dial.
This marking consists of three types. The first type of marking is
"WESTERN ELECTRIC MADE IN USA PAT APP FOR" on the case external circumference.The second type consists of marking "WESTERN
ELECTRIC PAT IN USA AUG 13 12 AUG 24 15 DES MAY 7 18 SEP 13 21 MADE IN
USA" on the case external circumference. This type appears to be
the most common and also the best looking when mounted in an early telephone.
The third type was the information of the second type but on the rear surface
of the case, with a plain external case circumference. Therefore,
the third type no longer had the information visible when mounted in a
telephone.

If the dial is removed from the telephone and
examined, it will be discovered that the type 1 case marking has two varieties.
The earliest type is stamped "2A" on the back of the case near the governor
flywheel. The other variety has no such stamp. These early
types also have different governors, main shafts which hold the finger
wheel, and case cut-outs for the switch pulse arm.

Other differences occur with internal parts.
These part differences consist of the following: switch screw contact insulators
(red, brown black, and layered red) four main shaft varieties, two purser
spring varieties (one of which silenced the clickety. clack), two finger
stop varieties (the type 3 being stronger) and two number plate supports.

During the 1930's many type 2 dials were modified
by the Bell System so that they would fit in the type D 202 telephone.
This modification consisted of changing the finger stop to a type which
bolted to the inside of the dial case instead of to the outside.
The dial face and support were also modified to accommodate the new finger
stop. These dials modified and unmodified, were used well into the
1940's. The modified dials used the "H" type of contact assembly
created for the B telephone introduced in 1928-1929.

The # 4 dial

To many of us, a Western Electric No. 4H dial
is a converted No. 2 dial which still has the loud clickety-clack sound
when dialed. The converted dial has had the old finger stop removed,
the holes plugged and a new finger stop installed. However there
is more to the No. 4 H dial than this simple description.

If the first thing you look for is those plugged
holes, you will soon discover that not all 4 H dials have the plugged holes!
The dials with the plugged holes are called "transitional' since they made
the transition from the No. 2 dial to the No. 4 H dial. The 4 H dials
without the plugged holes were regular production 4 H dials not conversions
of the earlier type. The transitional types were converted to satisfy
the demand until ample 4 H dials were available. This is typical
of the Bell System philosophy of never throwing anything away, and of continually
recycling equipment..

The 1930's saw the conversion of many No. 2 dials
to the 4 H configuration. These converted 4 H dials can properly
be referred to as "transitional" 4 H dials since they made the transition
from the No. 2 dial to the No. 4 H dial. All of the No. 2 types and
varieties mentioned before can be found in the transitional 4 H dials.
Of course this does not include the finger stop varieties of the No. 2
dials since the finger stops were removed and replaced in the transition
to the 4 H dial. The No. 2 dials were still being converted to transitional
dials in 1939 when a hybrid "E' type of contact assembly using parts from
the No. 2 switch assembly and the new 5 H contact assembly, just introduced
into the Bell System, were used. Fitting the hybrid switch assembly required
modification of the No. 2. This modification was similar to the elongated
hole in the 5 H dial case. Transitional dials also exist with complete
5 H switch assemblies.

Examination of the differences in the regular
production 4 H dials requires either partial disassembly or removal from
the telephone. The first obvious difference which is observed is
the method of painting the rear of the dial case. Up until this time
all dial cases were copper plated over a steel base and painted black.
However, the last type of 4 H dial did not depend on copper plating and
painting for corrosion resistance. Instead the case was chemically
treated and painting was only used to protect the screw threads.
This chemical treatment gave the dial a gray color on the unpainted areas.

The most obvious difference which is observed
in the 4 H painted case types is the method in which Western Electric marked
their name on the dial. All marking is on the rear surface of the
dial. This marking consists of two types. The earliest type
of marking is "WESTERN ELECTRIC MADE IN USA PAT IN USA AUG 24 15 DES MAY
7 18 SEPT 13 21" on the rear surface of the case. This type
used the following parts from the No. 2 dial: the main shaft, the
governor gear bracket, and the governor speed adjusting screw. The
second type of marking is "WESTERN ELECTRIC MADE IN USA PATENT 1151541
DES 52009 1390679" on the rear surface of the case. Apparently the
only part used from the No. 2 dial is the governor speed adjusting screw.

The type 4 H chemically treated case had the following
case marking: "WESTERN ELECTRIC MADE IN USA PATENT 1151541 DES 52009 1390679."
This dial incorporated a new stronger main shaft, a new governor gear bracket,
a governor with marks for adjusting the speed, a new stronger speed adjusting
screw, and a new dial face support to accommodate the new finger stop.
The composition of the "off center" switch actuator on the rear of the
dial was changed from steel to brass. The switch contact assembly
was largely unchanged from the 2 H type. Examination of the ends
of the individual contacts in the contact assembly reveals that the earliest
contacts are square cut and the latest are rounded on the ends. Those
in between are a gradual transition from square to round. Generally,
rounded cut contacts are either at the top or bottom of the contact stack
on type 2 dials, and usually only on variety 3 of the Type 2 series.
Transitional dials may have all rounded contacts if the assembly was replaced
in total during the transition. Since the bottom two contacts (or
the two contacts nearest the case edge) were added to the transitional
dials during the transition, they are generally always rounded. Type
4 dials should have all contacts rounded (transitional types excepted).

Clearly the type 4 H dial was still basically
a No. 2 with the incorporation of engineering improvements. This
dial still had the clickety-clack sound when dialed. The only varieties
the chemically treated case type 4 H dial is a slightly modified face support
which was changed in 1937. This dial can also be found with an unmodified
type 2 face support.

As an aside, in the mid 1930's the Bell System
converted from the type 132 dial face to the type 149 dial face also called
a number plate since the dial numbers were on the dial face. The
149 number plate had a kind of keyhole instead of a round hole for the
main shaft and was a better barrier against dirt. The 149 number
plate was constructed with a plastic protective layer- over the numbers
to protect against wear. A paper gasket was also installed under
the type 149 number plate to further prevent foreign material from entering
the dial.